Fujifilm Corporation

Fujinon Corporation

Nippon Hoso' Kyokai

Shinkichi Ikeda

Toshihiro Aoi

Takuya Tanaka

Masaru Yonezawa

Michio Cho

Yasutaka Shimada

Masanao Kawana

Takashi Kunugise

Daiki Komatsu

Arihiro Saita

Syunichiro Ouchi

Hideki Mitsumine

The zoom lens consists of a first lens group, a front group, a middle group, and a rear group, in order from an object side. The first lens group has a positive refractive power and includes a negative lens and a positive lens, successively in order from a position closest to the object side to an image side. The front group consists of one or more lens groups that move during zooming and has a negative refractive power as a whole throughout an entire zoom range. The middle group includes only one lens group as a lens group. The rear group consists of a plurality of lens groups. An aperture stop is disposed between a lens surface closest to the image side in the front group and a lens surface closest to the object side in the rear group. The zoom lens satisfies predetermined conditional expressions.

Zoom lens and imaging apparatus

The variable magnification optical system consists of a positive first lens group, an intermediate group, and a subsequent group in order from an object side to an image side, and does not form an intermediate real image in the entire zooming range. During zooming in a first zooming mode, a distance between the first lens group and the intermediate group changes, all distances between adjacent lens groups in the intermediate group change, a distance between the intermediate group and the subsequent group changes, and all distances between adjacent lens groups in the subsequent group are stationary. During zooming in the second zooming mode, all lens groups in the first lens group and the intermediate group are stationary, and all the distances of the adjacent lens groups in the subsequent group change. The zooming in the first zooming mode and the zooming in the second zooming mode can be independent.

Variable magnification optical system and imaging apparatus

A zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a positive fifth lens group. During zooming, the first lens group and the fifth lens group are not moved, and the second lens group, the third lens group, and the fourth lens group are moved. The second lens group includes a negative lens closest to the object side. In a case where a focal length of the second lens group is denoted by f2 and a focal length of the negative lens of the second lens group closest to the object side is denoted by f21, the zoom lens satisfies 0.6&#x3c;f2/f21&#x3c;0.9.

A zoom lens consists of a positive first lens group that is fixed during zooming, a negative second lens group that moves during zooming, a positive third lens group that moves during zooming, a positive fourth lens group that moves during zooming, and a positive fifth lens group that is fixed during zooming. During zooming from a wide angle end to a telephoto end, the fourth lens group moves from an image side to an object side, the second lens group and a composite group consisting of the third lens group and the fourth lens group pass through points where respective lateral magnifications are &#x2212;1 at the same time, the fifth lens group consists of a negative fifth A lens group that moves during anti-shake operation, and a positive fifth B lens group that is fixed during the anti-shake operation, and the lateral magnification of the fifth A lens group is negative.

The zoom lens includes, in order from the object side: a first lens group Gthat has a positive refractive power and remains stationary during zooming; a plurality of movable lens groups that move by changing distances between groups adjacent to each other in a direction of an optical axis during zooming; and a final lens group Ge that has a positive refractive power and remains stationary during zooming. At least one movable lens group has a negative refractive power. The first lens group Ghas an image side positive lens, which is a positive lens disposed to be closest to the image side, and one or more positive lenses which are disposed to be closer to the object side than the image side positive lens. The zoom lens satisfies predetermined conditional expressions relating to the image side positive lens.

The zoom lens consists of, in order from the object side, a first lens group that has a positive refractive power and remains stationary during zooming, a plurality of movable lens groups that move during zooming, and a final lens group that has a positive refractive power and remains stationary during zooming. The first lens group consists of, in order from the object side, a first lens group front group that has a negative refractive power, a first lens group intermediate group that has a positive refractive power and moves during focusing, and a first lens group rear group that has a positive refractive power. The first lens group front group has, successively in order from a position closest to the object side, a negative meniscus lens concave toward an image side, and a negative lens concave toward the object side. The components of the zoom lens satisfy predetermined conditional expressions.

Provided are a zoom lens which can be configured to have a small size while ensuring a high zoom ratio and has high optical performance by satisfactorily correcting chromatic aberration, and an imaging apparatus including the zoom lens. The zoom lens consists of, in order from the object side, a first lens group G1 that has a positive refractive power and remains stationary during zooming, a plurality of movable lens groups that move during zooming; and a final lens group Ge that has a positive refractive power and remains stationary during zooming. At least one movable lens group has a negative refractive power. The movable lens group, which is closest to the object side and has a negative refractive power, has two or more negative lenses, and satisfies predetermined conditional expressions.

The zoom lens consists of, in order from an object side: a first lens group that remains stationary during zooming and has a positive refractive power; at least two movable lens groups that are moved during zooming; and a final lens group that remains stationary during zooming and has a positive refractive power. The final lens group consists of, in order from the object side, a front group and a rear group. The front group has, successively in order from a position closest to the object side, two or less positive lenses and one first front group negative lens, and a second front group negative lens that is different from the first front group negative lens at a position closest to an image side and is concave toward the image side. An aperture stop is provided between the movable lens group and the first front group negative lens. The rear group consists of a positive lens and a rear group negative meniscus lens that is convex toward the image side. In addition, the zoom lens satisfies predetermined conditional expressions.

The zoom lens consists of, in order from an object side: a first lens group that remains stationary during zooming and has a positive refractive power; at least two movable lens groups that are moved during zooming; and a final lens group that remains stationary during zooming and has a positive refractive power. The first lens group consists of, in order from the object side, a first-a lens group that remains stationary during focusing and has a negative refractive power, a first-b lens group that is moved during focusing and has a positive refractive power, and a first-c lens group that remains stationary during focusing and has a positive refractive power. The first-a lens group consists of, in order from the object side, a first lens that has a negative refractive power, a second lens that is convex toward the object side and has a positive refractive power, and a third lens that has a negative refractive power. At least one of the first lens or the third lens satisfies a predetermined conditional expression, and the entire system satisfies the other predetermined conditional expressions.

A zoom lens consists of, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a positive refractive power, wherein magnification change is effected by changing all distances between adjacent lens groups. The second lens group is moved from the object side toward the image side during magnification change from the wide-angle end to the telephoto end. The position of the third lens group at the telephoto end is nearer to the image side than the position of the third lens group at the wide-angle end.

A zoom lens consists of five lens groups including, in order from the object side, positive, negative, positive, positive, and positive lens groups. During magnification change, the first and fifth lens groups are fixed relative to the image plane, and the second, third, and fourth lens groups are moved to change distances therebetween. During magnification change from the wide-angle end to the telephoto end, the second lens group is moved from the object side toward the image plane side, and the fourth lens group is moved from the image plane side toward the object side. The fifth lens group includes at least two negative lenses, and satisfies the condition expression (1) below:1.90&#x3c;&#x2003;&#x2003;(1).

A zoom lens consists of a positive first lens group, a negative second lens group moved from the object side to the image plane side during zooming from the wide angle end to the telephoto end, a positive third lens group moved during zooming, and a positive fourth lens group, in order from the object side. The second and third lens groups each pass through a point where the imaging magnification of each corresponding lens group is &#x2212;1&#xd7; at the same time during zooming from the wide angle end to the telephoto end. The fourth lens group includes, on the most object side, a vibration-proof lens group, composed of a negative lens, a positive meniscus lens with a convex surface on the object side, and a negative lens, in order from the object side, and either one of the negative lenses satisfies predetermined conditional expressions.

A zoom lens consists of a positive first lens group fixed during zooming, a negative second lens group moved during zooming, a positive third lens group moved during zooming to correct an image plane variation due to the zooming, and a positive fourth lens group fixed during zooming and includes a stop on the most object side. The second lens group includes two or more positive lenses and one or more negative lenses. The zoom lens satisfies predetermined conditional expressions with respect to the second lens group.

The zoom lens substantially consists of a positive first lens group fixed while changing magnification, a negative second lens group which moves from the object side to the image side while changing magnification, a positive third lens group which moves while changing magnification, and a positive fourth lens group which moves from the image side to the object side while changing magnification, and a positive fifth lens group fixed while changing magnification in this order from the object side. A floating system in which the third lens group and the fourth lens group move relative to each other while changing magnification is adopted. The image formation magnification rates of the combined lens group formed by the third lens group and the fourth lens group together and the second lens group simultaneously pass &#x2212;&#xd7; point while changing magnification from the wide angle end to the telephoto end.

The zoom lens substantially consists of a positive first lens group which is fixed while changing magnification, a negative second lens group which moves while changing magnification, a positive third lens group which moves while changing magnification, and a positive fourth lens group which is fixed while changing magnification in this order from the object side. The image formation magnification rates of the second lens group and the third lens group simultaneously pass a &#x2212;1&#xd7; point while changing magnification from the wide angle to the telephoto. The second lens group substantially consists of a negative second-a lens group and a positive second-b lens group which independently move while changing magnification in this order from the object side, and the third lens group substantially consists of a positive third-a lens group and a positive third-b lens group which independently move while changing magnification in this order from the object side.

Growing community of inventors

Saitama, Japan

Shinkichi Ikeda